Sample analyzers used in the fields of biochemistry, immunology, coagulation and the like, dispense reagent and sample into a reaction container and mix the reagent and the sample by agitating the liquid within the reaction container to prepare a measurement sample to be used for measurements.
United States Patent Application Publication No. 2011/0086432 discloses a mixing apparatus provided with a cuvette holder for holding a cuvette, a transport arm for moving the cuvette holder, a rubber disk disposed between the transport arm and the cuvette holder, an oscillating device including a motor, and an eccentric pin provided on the motor. The cuvette holder has a connector hole formed complementarily with the eccentric pin. The motor is fixed on a base at a predetermined position, and the transport arm is movable relative to the base. When mixing the sample within the cuvette, the transport arm is moved so that the connector hole of the cuvette holder is lowered onto the eccentric pin to connect the connector hole and the eccentric pin. The cuvette holder is oscillated by circular motion of the eccentric pin when the motor shaft is rotated, thus mixing the sample within the cuvette.
When the cuvette holder holds a cuvette in this mixing apparatus, the transport arm is moved to move the cuvette holder that does not hold a cuvette to a cuvette supplying position since a cuvette must be held in the cuvette holder. When sample or reagent is dispensed to the cuvette held in the cuvette holder, the transport arm must be moved to transfer the cuvette holder to the sample or reagent dispensing position so as to dispense the sample or reagent to the cuvette. However, it is difficult to ensure positional accuracy of the cuvette holder since the cuvette holder is supported on the transport arm only by the flexible rubber disk, hence concern that the cuvette will be inadequately supported in the cuvette holder.